The vCenter Server Appliance is the new vCenter Server. In the old days, we had a brand new Windows Server on which the vCenter Server was installed. The necessary database server was quite often an external MS SQL database and sometimes an internal database. In the those days, tweaking the Windows Server and the installed components was more or less a common practice, due to the familiarity with Windows.
But now the vCenter Server Appliance (vCSA) is the new and preferred standard. The vCSA comes as a virtual appliance and is ready to run within minutes compared to the old vCenter Server. Although a (virtual) appliance still means; (virtual) hardware, an operating system, middleware and applications, VMware likes to treat the vCSA as a “black box”. Like most appliances, the operating system is a Linux flavor and you can log in. After a successful log in, you will encounter the first discouragement; you are not welcomed by a Bash shell but with the default “Appliance Shell”. For more information read my post on the vCSA shells.
In this post, a brief introduction on the following topics; Appliance shell, File system and the Services.